Well equipment for recovery of hydrocarbons



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B. H. TOWELL ETAL WELL EQUIPMENT FOR RECOVERY OF HYDROCARBONS Filed Dec. 30, 1959 2 4 L a M a "V 474/ /z March 3, 1964 United States Patent Qfiice ilidddl Patented Mar. 3, 1954.-

3,123,141 ll ELL EfiUEWiENT FGER REVERY {PF HY R IBJARBUIS Billy H. Towel Iharies D. Woodward, and William V. Dean, lira, Yrlouston, Tex, assignors to Texaco Inc,

New York, FLY, a corporation of Delaware Filed Dec. 31}, 395" Scr. No. 362,877

(ill. res-es) This invention relates to improved equipment for the recovery of hydrocarbons from underground formations traversed by a well bore. More particularly, it relates to a novel combination of equipment inserted in a well bore traversing an underground formation from which hydrocarbons are to be recovered by thermal means.

The extreme conditions, particularly of temperature and pressure, involved in most thermal recovery processes necessitate the use of well producing equipment especially adapted to Withstand these conditions without rapid deterioration. Expensive producing equipment inserted down the well bore and positioned in or near the treated formation is subjected to the deteriorating heat produced. In addition, in many thermal recovery processes, air is injected through the well into the formation at high pressure to aid in the recovery. The mixing of a combustion supporting gas and fluid hydrocarbons produces a highly combustible composition which, when ignited in a confined space such as the well bore or pockets in the wall thereof, will explode with possible damage to well equipment therein, and to equipment and personnel at the surface above the well.

Certain parts of the equipment inserted in the well are necessarily subject to deterioration from excessive heat and must be protected to obtain performance for a reasonable length of time. Power supply leads in particular are composed of the type of materials which need protection from heat. It is with novel equipment which will meet these problems that the present invention is concerned.

In accordance with the present invention, improved equipment for recovery of hydrocarbons contained in an underground formation by a thermal recovery process and to be inserted in a well bore traversing said formation comprises, in combination, a fluid-tight sealing assembly capable Or isolating an upper from a lower portion of the well bore, a thermal equipment housing adapted to be inserted in said well bore below said sealing assembly, means to conduct a power supply between the surface and the thermal equipment in said housing through the sealing assembly, shielding means for said power supply conducting means extending through said sealing assembly to said housing, means to conduct a fluid flow down the well and through the sealing assembly, and means to direct the fiuid flow into the annulus surrounding said shielding means. in a preferred form, the invention pertains to equipment for an in situ combustion process and comprises flow tubing extending into said well, an electricity conducting lead extending into said well, a crossover assembly comprising a body member, an inner conduit connected to and extending below said body member, and an outer conduit around said inner conduit, said outer conduit connected to and extending below said body member, said body member having a passage extending from the upper end thereof to the inner conduit and a passage from the upper end thereof to the annular space between the inner and outer conduits, said flow tubing being in communication with the passage extending to the annular space and said electricity conducting lead extending through the other passage into said inner conduit, an electrical ignitor member attached to the lower end of said inner conduit, said electricity conducting means extending through said inner conduit and being connected to the head of said ignitor member, said outer conduit extending to near the head of the ignitor member whereby fluid flow is directed thereon and then into the lower portion of the well, and fluid-tight sealing means situated in the annulus between the outer conduit joined to the body member of the crossover assembly and the wall of the Well.

A complete understanding of the invention will be obtained by reading the following specification with reference to the accompanying drawing in which:

FIG. 1 is a cross-sectional view of a portion of a well bore containing the novel equipment of this invention; and

FIG. 2 is a cross-sectional view of the lower portion of the equipment of this invention.

The Well bore as seen in FIG. 1 is defined by the casing 22 having shoe 4. l e flow tubing d contains a ball check valve 8 and is attached at It? by threaded means or the like to the cross-over assembly broadly designated as 2. The cross-over assembly is shown to comprise a body member 14, an inner conduit 16 connected to the lower end of the body member 14- by threaded means and extending downwardly therefrom. An router conduit 1% surrounding the inner conduit 16 and attached to the body member 14 by threaded means is also a part of the cross-over assembly. The body member 14 is provided with a plurality of passages 2d from the upper end thereof to the annular space between the inner and outer conduits 16 and 18, respectively. The upper end of these passages 29 lead into the flow tubing 6 at its connection with the body member. The body member is also provided with passages 22 and 24 which extend from the upper end of the body member to the inner conduit. Passage 22 is provided for power conducting means such as electricity conducting lead 26 which extends through the passage 22 into the conduit 16. A stufiing box is provided at 23 to seal the annular space between the lead 26 and the wall of passage 22 thereby preventing the entrance of any fluid into the inner conduit 16. Passage -3- is provided in the body member 14 for another power conducting lead such as thermo-couple lead 36 which also passes into the inner conduit 16. Stuffing box 32 is provided to seal this passage and prevent any liquid from enterin the inner conduit 16. A number of passages such as 22 and 24 are usually provided in the body member 14 to accommodate other leads such as 2% and 3% which are necessary for the operation of thermal equipment lower in the well.

Packer 34 is positioned about the outer conduit 18 to provide a fluid-tight sealing means in the annulus between the cross-over assembly and the wall of the Well bore. The packer 34 can be of any or" the many known types as long as it will withstand the rigors of this kind or" recovery process. Packer 34 is activated by well known means not shown. Thus, the fluid-tight sealing assembly comprising the packer 34, outer conduit 1%, body member lid to which it is joined, and the stuffing boxes 28 an 32 with the leads 26 and 3d isolate the upper portion from the lower portion of the well bore.

in co-pending application, S.N. 863,044, filed even date herewith by Charles D. Woodward and Billy H. Toweil, it has been disclosed to provide pressure on the packer primarily as a safety measure to reduce the possibili y of down hole explosion and resulting well and equipment damage. Pressure is preferably provided by filling the well bore above the packer with water or brine. The novel equipment of this invention is particularly suited to the process where a fluid such as water or brine is used to apply downward pressure on the packer 34. Thus, power supply conduits can be conveniently passed from the upper portion of the well above the packer which contains a liquid into the lower portion of the Well downward to the thermal equipment.

In FIG. 2 the housing 3 is shown to be connected to inner conduit 16 by threaded means or the like at and leads 26 and 38 extend through the inner conduit 16 and are joined to the thermal equipment Broadly speaking, the thermal cc; arent can be a heater or ignitor supplied by either gas or electricity or a series of thermocouples used to measure the Ieat from an in situ combustion process wherein chemical or spontaneous ignition has been used to initiate combustion. it can be readily seen that combustion in the formation adjacent the well bore will subject the equipment to extreme tem peratures. The power supply leads are well protected as they leave the relatively cool portion of the well above the packer and proceed down through the shielding inner conduit 16 to the thermal equipment.

In one embodiment of this invention, an ignitor is used as the thermal equipment 38 for the initiation of in situ combustion. Since the temperature reached by electrical ignitors must be enough to ignite the hydrocarbons in the formation they also emit sufiicent heat to damage insulating material surrounding electrical power leads and thermocouple leads where these leads connect to or run close to the ignitor. Such hea could also damage the electrical power leads used to ignite gas in a gas ignitor. Such heat could also damage the thermocouple leads which are used in conjunction with the gas ig itor for monitoring tempera ure. Should a cornbustible mixture of gts be piped to a gas ignitor, excessive heat would cause a further hazard in terms of possible explosions in the gas-conducting pines above the gas ignitor. To overcome the possibility of damage to the equipment in the vic nity or" the ignitor 33, the outer conduit 18 of the cross-over assembly 12 is made to extend to just above the head 37 of ignitor housing as shown in PEG. 2, thereby conducting cool air at high velocity against that portion of the housing to prevent damage and to allow output of higher heat from the ignitor.

Obviously, many modifications and variations of the invention as hereinabove described may be made Without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated the appended claims.

We claim:

1. lrnproved equipment for recovery of hydrocarbons contained in an underground formation for use in a Well bore traversii I said formation comprising, in combination, a fluid-tight sealing assembly for said equipment capable of isolating the unper from the lower portion of said well bore and a housing with thermal equipment therein adapted to be inserted in said well bore below said sealing assembly, said assembly including a body member having a first passage for power supply conducting means, means to shield power supply conducting means from excessive heat surrounding the same joined to said body member and interconnecting said housing therewith, means joined to said body member to conduct a fluid flow down the said Well bore surrounding said means to shield power supply conducting means thereby defining an annulus therewith, said body member having a second passage to direct fluid flow into said annulus surrounding the shielding means.

2. The improved equipment of claim 1 wherein the power supply conducting means is electricity conducting means.

tight sealing assembly capable of isolating an upper portion of said well bore from a lower portion thereof joined to the bottom end of said flow tubing and includin a body member and an outer conduit joined thereto, said body member having a first passage for said passing from said upper portion into said lower portion of said well bore, a housing with thermal equipment therein situated below said sealing assembly, said thermal equipment being connected to the lower end of said electricity conducting lead, tubular heat shielding means surrounding said electricity conducting lead and interconnecting said housing with said body member and with said outer conduit below said sealing assembly dean annulus, said body member having a second passage to conduit fluid ilow from said flow tubing through said body member into said annulus surrounding said shielding means.

4. The improved equipment of claim 3 wherein said thermal equipment comprises an electrical ignitor memproved equipment for recovery of hydrocarbons contained in an underground formation for use in a well bore traversing said formation comprising, in combina tion, flow tubing extending into said well bore, a power supply conductor comprising an electricity conducting lead extending into said well bore, a cross-over assembly comprising a body member, an inner conduit connected to and extending below said body member, and an outer conduit connected to and extending below said body memher and surrounding said inner conduit thereby defining an annular soace therewith, said body member having a first passage extending from the upper end thereof to said inner conduit and a second passage from the upper end thereof leading to said annular space between the inner and outer conduits, said flow tubing being interconnected with said second passage extending to said annular space, said electricity conducting lead extending through said first passage into said inner conduit, a housing with an electrical ignitor therein attached to the lower end of said inner conduit, said electricity conducting lead extending through said inner conduit and being connected to said ignitor, and fluid-tight sealing means positioned to the annulus between the cross-over assembly and the wall of said well bore and situated intermediate said body member of said cross-over assembly and said housing.

6. The improved equipment of claim 5 wherein said outer conduit extends to the immediate vicinity of the connection of said inner conduit and said housing whereby fluid fiow will be directed onto said housing and then into said well bore.

References Cited in the file of this patent UNITED STATLS PATENTS 1,648,242 Powell Nov. 8, 1927 2,134,610 I-logg Oct. 25, 1938 2,703,621 Ford Mar. 8, 1955 2,771,951 Simm Nov. 27, 1956 2,889,881 Trantham et a1. June 9, 1959 

1. IMPROVED EQUIPMENT FOR RECOVERY OF HYDROCARBON CONTAINED IN AN UNDERGROUND FORMATION FOR USE IN A WELL BORE TRAVERSING SAID FORMATION COMPRISING, IN COMBINATION, A FLUID-TIGHT SEALING ASSEMBLY FOR SAID EQUIPMENT CAPABLE OF ISOLATING THE UPPER FROM THE LOWER PORTION OF 